Ring binders capture and retain hole-punched sheets such as loose-leaf paper, printed pages and advertisements, and photo sleeves. Such binders organize the sheets to form notebooks, pamphlets, reports, or files. Such binders typically include clips or rings for engaging the sheets via their punched holes. The most popular of such binders is generically referred to as a “ring binder” and is most commonly embodied with two rings (“two-ring binder”) or three rings (“three-ring binder”) which capture each sheet through holes punched adjacent its left side edge. The rings are typically made of two substantially semi-circular half rings that are engageable to form a continuous loop and are disengageable to form an open discontinuous loop. The ring halves are capable of being opened in clamshell fashion to receive or dispense sheets, or closed to retain the sheets in book-like format.
A problem common to prior art ring binder mechanisms lies in the often sharp tips of the ring halves and the quick and forceful snapping action as these tips move between their opened and closed positions. To address this safety problem, most recent ring binder mechanisms include an activator for forcing the rings opened or closed without the user having to touch the ring halves. However, even with this safety advantage available most prior art ring binder mechanisms still allowed the user to choose between either opening and closing the rings with the activator or opening the rings by grasping and pulling the ring halves apart and closing the rings by pushing the ring halves together. Many users, accustomed to the older mechanism or attracted by the prominence of the rings for grasping, continued to use the older and more dangerous opening and closing method. To address this, some recent ring binder mechanisms included a locking mechanism for preventing opening of the rings by grasping and pulling the ring halves, and incorporated this locking mechanism into the actuator. This ensured that that closing the rings simultaneously and automatically locks the ring halves together to prevent one form pulling the ring halves apart, but allows the rings to be automatically unlocked for opening during activation of the actuator. In order to open such mechanisms, the user must push the actuator from its closed to its opened position. Such mechanism will be generically referred to herein as “auto-locking” or “self-locking” ring binder mechanisms, but while they have improved over previous mechanisms, they continue to suffer from disadvantages and flaws.
An auto-locking ring binder mechanism is taught in US Publication 2007/0286670, which exemplifies some of the disadvantages and failings of such prior art auto-locking mechanisms. A pair of movable locking elements is swung between an open state and a closed state by movement of two wire links connected to the actuator to enable or block motion of a pair of hinge plates from the closed to the open position. The locking elements are then swung back as the actuator is moved to the open position so that they align with slots in the hinge plates and thereby allow the hinge plates to open only by actuation of the actuator.
Although hypothetically functional as depicted, in practical manufacture and use this mechanism is found difficult to produce and unreliable. The distance between the points of attachment of the wire links to the locking elements and actuator is very difficult to accurately control through the assembly of so many loose-fitting components. Yet movement of the locking elements by the actuator and wire links must be very precise to ensure that the locking elements take exact locking and unlocking positions in relation to the slots in the hinge plates. In practice, this often requires a slight manual bending of the wire links at assembly to ensure that the wires precisely mate with the remainder of the assembled components and accurately control the locking elements. Such bend-ability requires that the links be made of the thin and flexible wire as shown. During real-world use, these wire links are found incapable of withstanding the common and reasonably anticipated misuses that such binders should be able to withstand.
The wires must be attached to the locking elements at an off-center position as depicted in order to cause the swinging of the elements, requiring the wire links to follow an arcuate path during their translation and create a non-straight line of force between the actuator, link, and element. It is common for occasional excessive forces to be inadvertently applied to the actuator or rings during unintentional misuse, such as to try to force the mechanism closed against an obstruction, and such forces are transmitted along the bendable wire links. With the non-straight arrangement required in this design, the wire links are easily bent by these forces and the distance between the points of attachment that was so carefully set during production is instantly changed. So the mechanism that was may have been functional at the time of manufacture is rendered nonfunctional by such common and reasonably anticipated misuse.
Additionally, the swinging motion of the locking elements in the above-described mechanism causes them to scrape against the hinge plates. Since the edges of the locking elements are naturally sharp and the swinging motion is arcuate, this causes wear and binding as the locking element rubs against the hinge plates, creates objectionable noise, obstructs the movement, and ultimately renders the mechanism unreliable and short-lived.
Numerous other prior art ring binder mechanisms employ linear translating locking elements, which share the disadvantage stated above because the sharp locking elements scrape against the hinge plates in a linear motion that causes similar wear and binding, noise, obstruction, and ultimate unreliability and short-life as well.
Additionally, because the binders in which such mechanisms are sold tend to be low-cost commodities, the mechanisms must be very inexpensive to manufacture. As a result, the mechanisms of the prior art must generally be constructed of thin gauge metal stampings and wires. The dimensions and shapes of such components are inherently difficult to control. This has resulted in an inability to manufacture many prior art mechanisms in a real-world application, even though such mechanisms promise to work perfectly as drawn.
Accordingly, disadvantages and flaws common to prior art ring binder mechanisms lie in the lack of reliability inherent in their designs. Disadvantages and flaws lie in the lack of structural rigidity dictated by their various constructions. Disadvantages and flaws lie in the manufacturing difficulties dictated by their complexity. Disadvantages and flaws lie in the high cost of manufacturing dictated by their numbers and types or components. And disadvantages and flaws lie in the lack of dimensional control of the components dictated by their required manufacturing methods. Further disadvantages and flaws will be readily appreciated by those familiar with the art.
There exists a need to overcome the lack of reliability inherent in the designs of prior art ring binders and ring binder mechanisms, and such is an object of the present invention. There exists a need to overcome the lack of structural rigidity dictated by the various constructions of prior art ring binders and ring binder mechanisms, and such is another object of the present invention. There exists a need to overcome the manufacturing difficulties dictated by the complexities of prior art ring binders and ring binder mechanisms, and such is another object of the present invention. There exists a need to overcome the high cost of manufacturing dictated by the numbers and types or components of prior art ring binders and ring binder mechanisms, and such is another object of the present invention. There exists the need for an arrangement and construction for a ring binder mechanism that is immune from the lack of dimensional control dictated by prior at arrangements and constructions, and such is another object of the present invention. Further needs and objects exist which are addressed by the present invention, as may become apparent by the included disclosure of an exemplary embodiment thereof.